Apple will release iOS 9 to the public on September 16

SAN FRANCISCO—Apple officially announced iOS 9 at WWDC in June, and adventurous users could start playing with the public beta in July, but today the company announced a public release date for the finished version of the operating system: Wednesday, September 16.

The software update will arrive a couple of days ahead of Apple's latest iPhones, which was to be expected given Apple's past behavior. An unexpected benefit of this release is that it won't drop support for any device currently running iOS 8—iOS 9.0 will run on iPhones as old as 2011's 4S, iPads as old as 2011's iPad 2 or 2012's iPad Mini, and both the fifth- and sixth-generation iPod Touch.

The new operating system is mostly about refinements, at least on small-screened iDevices. iOS 7's Helvetica Neue system typeface has been replaced by San Francisco, which first showed up in the Apple Watch. The default software keyboard switches between lower- and uppercase letters, fixing the ambiguous Shift key. Spotlight can now tap into third-party apps and attempts to present you information proactively based on your habits. Siri and the multitasking switcher have new looks, the Settings app has a search function, and there are other small visual and functional changes sprinkled throughout the operating system.